Credit and debit cards are widely used to conduct commerce across the globe. The current credit card system has been largely based on a coding of alphanumeric characters on the front of the card that make up the credit card account numbers, along with characters on the front and back of the cards or other security devices such as holographic stickers to provide secondary security and identification measures. Magnetic stripes on the back of cards are also a common feature. These stripes are used to encode a secure, unique digital data sequence that is read by the electronic magnetic card reader stripe swiping system and used to validate the card at manned and automated retail checkout counters. In utilizing these basic systems, as well as other systems, the credit card business has enjoyed a business that has grown in size each year with hundreds of billions of dollars spent by consumers with credit and debit cards each year.
The current system for coding and verifying credit card accounts and corresponding security checks is well established. For transactions occurring over the phone, or for online transactions, credit card users often input both their primary card account number, as well as, a secondary account number and an expiration date. Additionally, card account holders may be asked to input their address and sometimes even personal pin numbers. In some cases, they may be asked to answer a personal question stored by the card company, such as the name of their “favorite pet” or their “mother-in-law.”
Conventional models address the need to create unique account numbers, and to provide other means to verify those account numbers and their corresponding users. These other means include the use of an expiration date or security code printed on the front and back of a card, or the use of a magnetic stripe holding programmed information. The magnetic stripe is an institutionalized technology in the credit and debit card industry. Today financial cards all follow the ISO standards to ensure read reliability world wide and along with transit cards constitute the largest users of magnetic stripe cards.
The magnetic stripe is written and read in much the same way that audio recording tape is written and read, except that the data are binary digits—1s and 0s—instead of sounds. The magnetic stripe is made of a material that can be magnetized. To write data onto the stripe, the card is dragged over a tiny electromagnet. Pulses of electrical current are pushed through the electromagnet windings in one direction or the other, to magnetize tiny spots on the stripe material. Perhaps one direction of magnetization represents a “1”, while the opposite direction represents a “0”; but more likely a slightly more complicated system is used. Companies that deal with these cards have agreed among themselves how to use arrangements of 1s and 0s to represent the letters and numbers that they want to store on the stripe.
To read the data, the card is dragged over a tiny coil of wire. Movement of the magnetized spots past the coil causes small electrical voltages to appear in the coil, and from these voltages the stored 1s and 0s can be deduced. In practice, the coil used to read the stripe is very similar to the electromagnet used to write the stripe. These electromagnets are mounted in “write heads” and “read heads”, which typically hold not one but several electromagnets, side by side, so that several “tracks” of magnetized spots are written and read simultaneously.
A standard card employing a magnetic stripe may have any of three tracks, or a combination of these tracks. Track 1 was the first track standardized. This layout was developed by the International Air Transportation Association (IATA) and is still reserved for their use. The layout includes 210 bits per inch (“bpi”), meaning the number or 0s or 1s that one head can write on each inch of stripe, with room for 79 numeric characters. It includes the primary account number (up to 18 digits) and the account holder's name (up to 26 alphanumeric characters).
Track 2 was developed by the American Bankers Association (ABA) for on-line financial transactions. This layout includes 75 bpi with room for 40 numeric characters. It includes the account number (up to 19 digits).
Track 3 is also used for financial transactions. The difference is its read/write ability. The layout includes 210 bpi with room for 107 numeric digits. It also includes an enciphered PIN, country code, currency units, amount authorized, subsidiary account information and other restrictions.
Instead of, or in addition to simply using magnetic stripes that store data, cards may also contain microcontrollers that store data and run programs. These “smartcards” contain an internal microcontroller that runs a program as soon as it is inserted in a smartcard socket. The firmware running in the smartcard is an interpreter with a passive nature, which means that instead of initiating its own actions, it merely responds in a predetermined way to commands sent in from the outside world. Furthermore, like most modern microcontrollers, its program memory can be locked so that it can be neither examined nor modified by any external means. Smartcards generally contain encryption routines built in their firmware. The combination of the three aforementioned characteristics makes these devices particularly well suited for applications requiring high security.
Furthermore, another security measure includes the use of optical memory cards. Optical memory cards use a technology similar to the one used with music CDs or CD ROMs. A panel of the “gold colored” laser sensitive material is laminated in the card and is used to store the information. The material is comprised of several layers that react when a laser light is directed at them. The laser burns a tiny hole (2.25 microns in diameter) in the material which can then be sensed by a low power laser during the read cycle. The presence or absence of the burn spot indicates a “one” or a “zero.” Because the material is actually burned during the write cycle, the media is a write once read many (WORM) media and the data is non volatile (not lost when power is removed).
Optical cards can currently store between 4 and 6.6 MB of data which gives the ability to store graphical images (e.g. photographs, logos, fingerprints, x-rays, etc.). The data is encoded in a linear x-y format. ISO/IEC 11693 and 11694 standards provide details regarding the encoding format. The primary users of optical technology today are: the medical and healthcare industry; prepaid debit cards; cargo manifests; admission pass season tickets; auto maintenance records; and retail purchase cards and RFID embedded chips to help ensure security, validity and proper use of the credit or debit cards.